Interventional EUS (with videos)

Endoscopic Ultrasound-Guided vs Endoscopic Retrograde Cholangiopancreatography-Guided Biliary Drainage as Primary Approach to Malignant Distal Biliary Obstruction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

Endoscopic ultrasound-guided biliary drainage (EUS-BD) is an alternative to endoscopic retrograde cholangiopancreatography (ERCP)-guided transpapillary drainage in malignant distal biliary obstruction (MDBO). This meta-analysis of randomized controlled trials (RCTs) aims to compare the outcomes of these 2 approaches.

METHODS

Electronic databases from January 2005 through December 2023 were searched for RCTs comparing outcomes of EUS-BD and ERCP for treating MDBO. Pooled proportions, risk ratio (RR), and odds ratio were calculated using random-effects models.

RESULTS

Five RCTs comprising 519 patients were included in the final analysis. The pooled RR for overall technical success with EUS-BD compared with ERCP was 1.05 (95% confidence interval [CI] = 0.96-1.16, P = 0.246, I2 = 61%) and for clinical success was 0.99 (95% CI = 0.95-1.04, P = 0.850, I2 = 0%). The pooled rate of procedure-related pancreatitis was 7.20% (95% CI = 3.60-13.80, I2 = 34%) in the ERCP group compared with zero in the EUS-BD group. The pooled RR for stent dysfunction with EUS-BD compared with ERCP was 0.48 (95% CI = 0.28-0.83, P = 0.008, I2 = 7%). The weighted mean procedure time was 13.43 (SD = 10.12) minutes for EUS-BD compared with 21.06 (SD = 6.64) minutes for ERCP. The mean stent patency was 194.11 (SD = 52.12) days in the EUS-BD group and 187 (SD = 60.70) days in the ERCP group.

DISCUSSION

EUS-BD is an efficient and safe alternative to ERCP in MDBO. An almost nonexistent risk of procedure-related pancreatitis, lower procedure time, and ease of use make this an attractive primary approach to biliary decompression in centers with expertise.

Analysis of the variation in learning curves for achieving competency in convex EUS training: a prospective cohort study using a standardized assessment tool

BACKGROUND AND AIMS

The need for mastering standard imaging techniques for convex EUS in the biliopancreatic regions has been increasing; however, large variations in the aptitude for achieving EUS competency hinder expert development. Therefore, we investigated the factors influencing the achievement of expert competency in EUS using a new assessment tool for multiple imaging items.

METHODS

Between January 2018 and February 2022, 3277 consecutive EUS procedures conducted by 5 beginners (EUS procedures <250), 7 intermediate trainees (250-749), and 2 experts (≥750) were prospectively evaluated. Immediately after each EUS procedure, the success or failure of imaging for each item was recorded using a newly developed EUS assessment tool that requires 17 items to be photographed. After correcting for missing values using multiple imputation, learning curves of EUS scores were created, and a competency was set based on expert scores. Finally, a comparative analysis between high and low performers was performed to extract factors influencing EUS scores.

RESULTS

Although 3 of 7 intermediates (43%; mean, 317 cases) achieved competency, none of the beginners achieved competency. During a comparative analysis, although no significant difference in the number of EUS procedures performed was observed between the high and low performers, the former had significantly higher scores in the written test (theoretical knowledge).

CONCLUSIONS

Our results showed that theoretical knowledge, rather than the number of EUS cases, may be a possible influencing factor for distinguishing high and low performers after treating 250 cases. (Clinical trial registration number: UMIN 000043271.).

Evaluation of an all-in-one hybrid model (EUS Magic Box) for stepwise teaching and training in multiple interventional EUS procedures

Background and study aims  While multiple interventional endoscopic ultrasound (EUS)-guided procedures have evolved over the past two decades, there is no model that allows for training in all of these procedures. We aimed to develop and validate an all-in-one hybrid model for stepwise learning in multiple EUS interventions. Methods  A hybrid model was created utilizing a pig esophagus and stomach, a silicon-based duodenum and pancreato-biliary system, a pseudocyst, and biopsy targets. This model was designed to provide hands-on training in multiple interventional EUS procedures, such as EUS-guided fine-needle biopsy (EUS-FNB), biliary drainage (BD), pancreatic duct drainage (PD), pseudocyst drainage (PSD), and gastro-enterostomy (GE). Thirty-six trainees underwent training on this model over 6 days, in two batches. Lumen apposing metal stents were used for PSD and GE. Trainees were assessed for objective criteria of technical difficulties. Subjective assessment by trainees was done via a questionnaire. Results  All the trainees were able to complete the requisite steps for all the procedures under supervision. On subjective assessment, 30 trainees (83 %) graded the model as good or excellent. A total of 107 technical difficulties were noted (scope position 55, duct puncture 27, guidewire-related problems 25). Time taken to complete the requisite steps of biopsy, PSD, and GE (10.5 minutes; range 3.5 to 22) was significantly less than that for BD and PD (28 minutes; range 17 to 40) ( P  < 0.001). Conclusions  The hybrid model provided training for multiple EUS interventions with good acceptance by trainees. Stepwise mentoring with the possibility of performing multiple procedures in a single model with or without X-ray could prove useful in conference as well as institutional settings.

Compliance to endoscopic retrograde cholangiopancreatography according to current guidelines and adverse outcomes of suspected choledocholithiasis in an acute care setting

INTRODUCTION

Common bile duct (CBD) stones are common among patients who underwent cholecystectomy. However, few studies have investigated the compliance with the guidelines for the prediction of choledochlithiasis (CL). Therefore, we aim to study the compliance with the American Society for Gastrointestinal Endoscopy (ASGE) guidelines for the identification of CL in a major hospital in Saudi Arabia's capital.

METHODS

We conducted a retrospective chart review on adult patients admitted to emergency department at King Abdulaziz Medical City, Riyadh with gallstones between January 2016 and January 2019. Our data collection includes demographics and level of suspicion based on Transabdominal Ultrasound, liver function, amylase, and lipase tests. We then determined the likelihood of CL based on ASGE guidelines in order to assess the adherence to ASGE guidelines, the procedure's outcomes and adverse outcomes.

RESULTS

We identified 826 patients who met the study's criteria: 384 (46.4%) were compliant, while 442 (53.6%) were non-compliant with ASGE guidelines. There was a significant association between compliance and the presence of stones on ERCP in high likelihood patients. 48 (21.3%) of total ERCP procedures among all the likelihoods had adverse outcomes. 13 (40.6%) of non-compliant ERCP performed in intermediate likelihood have experienced adverse outcomes. There was a significant association between having adverse outcomes and being non-complaint with ASGE guidelines.

CONCLUSION

Despite ASGE guidelines' recommendations, a third of high likelihood cases and the majority of intermediate likelihood cases were non-compliant. Additionally, the current guidelines for the intermediate group are somewhat vague, giving ample leeway for patients to be placed in the intermediate group, which might subject them to unnecessary interventions. To conclude, there was a great lack of compliance with ASGE guidelines that is significantly associated with adverse outcomes. Hence, reassessing the current guidelines and monitoring healthcare facilities' compliance with the updated guidelines is highly recommended.

Efficacy and Safety of EUS-Guided Choledochoduodenostomy Using Electrocautery-Enhanced Lumen-Apposing Metal Stents (ECE-LAMS) in the Treatment of Biliary Obstruction: A Systematic Review and Meta-Analysis

Background. Electrocautery-enhanced lumen-apposing metal stents (ECE-LAMS) have been newly developed to perform EUS-guided choledochoduodenostomy (EUS-CDS), but its benefits and harms remain obscure. We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of EUS-CDS using ECE-LAMS. Method. In the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we searched PubMed, Embase, and Scopus databases through January 1, 2001, and April 27, 2020. The primary outcomes of the pooled analysis were to determine the technical success, clinical success, and overall adverse events rates. The secondary outcomes were pooled rates of short-term and long-term adverse events. Results. Six studies with 270 patients were finally included in this meta-analysis. The pooled rates of technical, clinical success, and adverse events were 95.1% (95% CI = 90.6–97.5%, I2 = 25%), 93.3% (95% CI = 87.4–96.5%, I2 = 28%), and 15.3% (95% CI = 10.6–21.6%, I2 = 13%), respectively. The pooled rates of short-term and long-term adverse events were 3.6% (95% CI = 1.3–9.6%, I2 = 0%) and 11.3% (95% CI = 7.6–16.5%, I2 = 0%), respectively. Conclusion. EUS-CDS using ECE-LAMS provides favorable outcomes in patients with biliary obstruction. It has been associated with a higher success rate and a lower rate of adverse events when compared with the biliary drainage approaches previously used. Large and randomized controlled observational studies are required to further refine the findings in the present analysis.

Endoscopic devices and techniques for the management of bariatric surgical adverse events (with videos)

BACKGROUND AND AIMS

As the prevalence of obesity continues to rise, increasing numbers of patients undergo bariatric surgery. Management of adverse events of bariatric surgery may be challenging and often requires a multidisciplinary approach. Endoscopic intervention is often the first line of therapy for management of these adverse events. This document reviews technologies and techniques used for endoscopic management of adverse events of bariatric surgery, organized by surgery type.

METHODS

The MEDLINE database was searched through May 2018 for articles related to endoscopic management of adverse events of bariatric interventions by using relevant keywords such as adverse events related to "gastric bypass," "sleeve gastrectomy," "laparoscopic adjustable banding," and "vertical banded sleeve gastroplasty," in addition to "endoscopic treatment" and "endoscopic management," among others. Available data regarding efficacy, safety, and financial considerations are summarized.

RESULTS

Common adverse events of bariatric surgery include anastomotic ulcers, luminal stenoses, fistulae/leaks, and inadequate initial weight loss or weight regain. Devices used for endoscopic management of bariatric surgical adverse events include balloon dilators (hydrostatic, pneumatic), mechanical closure devices (clips, endoscopic suturing system, endoscopic plication platform), luminal stents (covered esophageal stents, lumen-apposing metal stents, plastic stents), and thermal therapy (argon plasma coagulation, needle-knives), among others. Available data, composed mainly of case series and retrospective cohort studies, support the primary role of endoscopic management. Multiple procedures and techniques are often required to achieve clinical success, and existing management algorithms are evolving.

CONCLUSIONS

Endoscopy is a less invasive alternative for management of adverse events of bariatric surgery and for revisional procedures. Endoscopic procedures are frequently performed in the context of multidisciplinary management with bariatric surgeons and interventional radiologists. Treatment algorithms and standards of practice for endoscopic management will continue to be refined as new dedicated technology and data emerge.

Multicenter, randomized comparison of the diagnostic accuracy of 19-gauge stainless steel and nitinol-based needles for endoscopic ultrasound-guided fine-needle biopsy of solid pancreatic masses

BACKGROUND

The use of 19-gauge (G) stainless steel needles for endoscopic ultrasound-guided fine-needle biopsy of a pancreatic mass often results in technical difficulties due to an inability to advance the relatively rigid needle out of the endoscope. More flexible nitinol-based needles might decrease such technical difficulties and thus increase diagnostic accuracy.

OBJECTIVE

In this prospective multicenter randomized single-blinded study we compared the diagnostic value of those two needle types in patients with a solid pancreatic lesion.

METHODS

Patients with a solid pancreatic mass were diagnosed with endoscopic ultrasound-guided fine-needle biopsy using one puncture with each needle in a randomized fashion. The primary endpoint was the diagnostic accuracy of each needle. Secondary endpoints included time for puncture, amount of tumour tissue obtained, and technical failure. Histological specimens were centrally reviewed by a pathologist blinded to the final needle type and final diagnosis (ClinicalTrials.gov Identifier: NCT02909530).

RESULTS

Out of 46 prospectively recruited patients, central pathological examination was available for 41. Diagnostic accuracy for the two needles combined was 87.8%. Diagnostic accuracy was 66% and 68% using the stainless steel- and nitinol-based needle respectively. Time spent for puncturing was 137 ± 61 s (mean ± standard deviation) for the stainless steel and 111 ± 53 s for the nitinol-based needle (p = 0.037). Technical failure occurred in three (6.5%) cases using the stainless steel- and in none using the nitinol-based needle.

CONCLUSIONS

Usage of a nitinol-based 19-G needle failed to present a significant superior accuracy compared with a stainless steel needle in endoscopic ultrasound-guided fine-needle biopsy of solid pancreatic lesions.

Lumen-apposing metal stents for malignant biliary obstruction: Is this the ultimate horizon of our experience?

In the last years, endoscopic ultrasonography (EUS) has evolved from a purely diagnostic technique to a more and more complex interventional procedure, with the possibility to perform several type of therapeutic interventions. Among these, EUS-guided biliary drainage (BD) is gaining popularity as a therapeutic approach after failed endoscopic retrograde cholangiopancreatography in distal malignant biliary obstruction (MBO), due to the avoidance of external drainage, a lower rate of adverse events and re-interventions, and lower costs compared to percutaneous trans-hepatic BD. Initially, devices created for luminal procedures (e.g., luminal biliary stents) have been adapted to the new trans-luminal EUS-guided interventions, with predictable shortcomings in technical success, outcome and adverse events. More recently, new metal stents specifically designed for transluminal drainage, namely lumen-apposing metal stents (LAMS), have been made available for EUS-guided procedures. An electrocautery enhanced delivery system (EC-LAMS), which allows direct access of the delivery system to the target lumen, has subsequently simplified the classic multi-step procedure of EUS-guided drainages. EUS-BD using LAMS and EC-LAMS has been demonstrated effective and safe, and currently seems one of the most performing techniques for EUS-BD. In this Review, we summarize the evolution of the EUS-BD in distal MBO, focusing on the novelty of LAMS and analyzing the unresolved questions about the possible role of EUS as the first therapeutic option to achieve BD in this setting of patients.

Health-related quality of life and long-term outcomes after endoscopic therapy for walled-off pancreatic necrosis

BACKGROUND AND AIM

Walled-off pancreatic necrosis (WON) frequently develops after necrotizing pancreatitis. Endoscopic drainage has become the preferred modality for symptomatic or infected WON. The aim of the present study was to assess health-related quality of life (HR-QOL) and long-term outcomes in patients undergoing endoscopic drainage for WON.

METHODS

Patients undergoing endoscopic drainage of WON from January 2006 to May 2016 were identified. Data recorded included demographic information, and the incidence of long-term sequelae including pancreatic endocrine and exocrine insufficiency. Attempts were made to contact all patients. HR-QOL was assessed using the SF-36 questionnaire.

RESULTS

Eighty patients were analyzed, 41 (51.3%) of whom completed the SF-36. One-year all-cause mortality was 6.2%, and disease-related mortality was 3.7%. A notable proportion of patients developed exocrine insufficiency (32.5%), endocrine insufficiency (27.7%), and long-term opiate use (42.5%). Development of exocrine insufficiency was predictive of lower total SF-36 scores (P = 0.016). Patients with WON had better HR-QOL compared with cohorts of irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). In patients developing exocrine insufficiency versus healthy controls, poorer scores in the physical role (P < 0.001), general health (P < 0.001), vitality (P = 0.001), and emotional role (P = 0.029) domains were observed. Exocrine insufficiency patients had better HR-QOL than the IBS and IBD cohorts, although these differences were less pronounced.

CONCLUSION

After undergoing endoscopic drainage for WON, patients have relatively preserved HR-QOL. The subset of patients that develop exocrine insufficiency have significantly poorer HR-QOL compared to healthy controls, although not to the degree of chronic gastrointestinal disorders such as IBS and IBD.

Burden and Cost of Gastrointestinal, Liver, and Pancreatic Diseases in the United States: Update 2018

BACKGROUND & AIMS

Estimates of disease burden can inform national health priorities for research, clinical care, and policy. We aimed to estimate health care use and spending among gastrointestinal (GI) (including luminal, liver, and pancreatic) diseases in the United States.

METHODS

We estimated health care use and spending based on the most currently available administrative claims from commercial and Medicare Supplemental plans, data from the GI Quality Improvement Consortium Registry, and national databases.

RESULTS

In 2015, annual health care expenditures for gastrointestinal diseases totaled $135.9 billion. Hepatitis ($23.3 billion), esophageal disorders ($18.1 billion), biliary tract disease ($10.3 billion), abdominal pain ($10.2 billion), and inflammatory bowel disease ($7.2 billion) were the most expensive. Yearly, there were more than 54.4 million ambulatory visits with a primary diagnosis for a GI disease, 3.0 million hospital admissions, and 540,500 all-cause 30-day readmissions. There were 266,600 new cases of GI cancers diagnosed and 144,300 cancer deaths. Each year, there were 97,700 deaths from non-malignant GI diseases. An estimated 11.0 million colonoscopies, 6.1 million upper endoscopies, 313,000 flexible sigmoidoscopies, 178,400 upper endoscopic ultrasound examinations, and 169,500 endoscopic retrograde cholangiopancreatography procedures were performed annually. Among average-risk persons aged 50-75 years who underwent colonoscopy, 34.6% had 1 or more adenomatous polyps, 4.7% had 1 or more advanced adenomatous polyps, and 5.7% had 1 or more serrated polyps removed.

CONCLUSIONS

GI diseases contribute substantially to health care use in the United States. Total expenditures for GI diseases are $135.9 billion annually-greater than for other common diseases. Expenditures are likely to continue increasing.

Lumen Apposing Metal Stents (LAMSs) for Drainage of Pancreatic and Gallbladder Collections: A Meta-analysis

BACKGROUND AND AIMS

Endoscopic ultrasound-guided transmural drainage using lumen apposing metal stents (LAMSs) is becoming a popular and promising therapeutic approach for drainage of intra-abdominal fluid collections. There has been an increasing number of studies evaluating LAMS for drainage of pancreatic pseudocysts (PP), walled-off pancreatic necrosis (WOPN), and gallbladder (GB) drainage. The aim of this meta-analysis is to analyze the literature to date regarding the clinical success, technical success, and adverse events of LAMS in treatment of pancreatic fluid collections and GB drainage.

METHODS

A comprehensive search of multiple literature databases through November 2016 was performed. Human studies with at least 10 subjects that examined the clinical success, technical success, and adverse events of LAMS in treating PP, WOPN, and GB drainage were included.

RESULTS

A total of 993 patients (608-WOPN; 204-PP; 181-GB drainage) underwent drainage from 20 trials. For drainage of WOPN, the pooled technical success was 98.9% [95% confidence interval (CI): 98.2% to 99.7%] and clinical success was 90% (95% CI: 87% to 93%) (τ=0.001). For drainage of PP, the pooled technical success was 97% (95% CI: 95% to 99%) and clinical success was 98% (95% CI: 96% to 100%), (τ=0.001). For GB drainage, the pooled technical success was 95% (95% CI: 91% to 99%) and clinical success was 93% (95% CI: 90% to 97%), (τ=0.001). Total adverse events occurred in 11% of patients with higher complication rates observed in GB drainage. There was no evidence of publication bias in this meta-analysis.

CONCLUSIONS

Endoscopic ultrasound-guided transmural drainage using LAMS is becoming a widely accepted therapeutic approach for the treatment of PP, WOPN, and GB drainage with high clinical and technical success rates and acceptable adverse events. Further prospective randomized trials reporting long-term clinical efficacy and cost-effectiveness are needed to validate LAMS as a therapeutic modality for pancreatic and GB collections.

Updates in Therapeutic Endoscopic Ultrasonography

The last decade has seen a dramatic rise in the possibilities of therapeutic endoscopic ultrasound (EUS). From EUS fine needle aspiration of cancerous lesion to pseudocyst drainage, it has now not only replaced some of the percutaneous techniques but has permitted to bypass all together laparoscopic approach for patient with altered anatomy or malignant gastric outlet obstruction. This review will emphasize the novel therapeutic EUS procedures added to our arsenal.

Stent placement by EUS or ERCP for primary biliary decompression in pancreatic cancer: a randomized trial (with videos)

BACKGROUND AND AIMS

Studies on EUS-guided transmural biliary drainage (EUS-BD) have evaluated its efficacy as a rescue technique after failed ERCP. We performed a single-center, single-blind, randomized trial to compare EUS-BD and ERCP as primary treatment for distal biliary obstruction in pancreatic cancer.

METHODS

Patients underwent EUS-BD (n = 33) or ERCP (n = 34). The primary endpoint was the rate of adverse events. Secondary endpoints were technical success, treatment success (defined as decline in serum bilirubin by 50% at a 2-week follow-up), reinterventions, and intraoperative technical outcome, when applicable. Follow-up was until death or a minimum of 6 months.

RESULTS

The rates of adverse events were 21.2% (6.1% moderate severity; others mild severity) in the EUS-BD group and 14.7% (5.9% moderate severity; others mild severity) in the ERCP group (risk ratio, .69; 95% confidence interval, .24-1.97; P = .49). There were no procedure-related deaths. There was no significant difference in the rates of technical success (90.9% vs 94.1%, P = .67), treatment success (97% vs 91.2%, P = .61), or reinterventions (3.0% vs 2.9%, P = .99) between EUS-BD and ERCP cohorts, respectively. The endoscopic interventions did not impede subsequent pancreaticoduodenectomy that was performed in 5 of 33 patients (15.2%) in the EUS-BD and 5 of 34 patients (14.7%) in the ERCP group (P = .99).

CONCLUSIONS

Given the similar rates of adverse events and treatment outcomes in this randomized trial, EUS-BD is a practical alternative to ERCP for primary biliary decompression in pancreatic cancer. (Clinical trial registration number: NCT03054987.).

Endoscopic ultrasound-guided hepaticogastrostomy and antegrade clearance of biliary lithiasis in patients with surgically-altered anatomy

BACKGROUND AND STUDY AIMS

 Endoscopic retrograde cholangiography (ERC) in patients with complex surgically-altered anatomy (SAA) is technically demanding and has limitations. Developments in EUS-guided procedures allow alternative approaches for patients with altered gastrointestinal anatomy and biliary lithiasis.

PATIENTS AND METHODS

 Single-center, retrospective review of prospectively entered patients with SAA who underwent EUS-guided hepaticogastrostomy (HGS) followed by an interval antegrade endoscopic clearance of biliary lithiasis.

RESULTS

 9 patients with Roux-en-Y anatomy underwent HGS to allow clearance of biliary lithiasis after a mean of 2.5 procedures. Technical success was achieved in 100 % of patients utilizing subsequent antegrade endoscopic techniques after HGS including: balloon sweep (9), transpapillary balloon dilation (8), cholangioscopy with electrohydraulic lithotripsy (4), and mechanical lithotripsy (1). HGS stents were removed in all patients. 1 adverse event (cholangitis) occurred after cholangioscopy and prolonged intraductal electrohydraulic lithotripsy.

CONCLUSION

 EUS-guided antegrade therapy for the management of biliary lithiasis in patients with altered gastrointestinal anatomy appears efficacious with a low risk of adverse events. These preliminary results suggest this approach should be considered at centers with available expertise.

Usefulness of combined percutaneous-endoscopic rendezvous techniques after failed therapeutic endoscopic retrograde cholangiography in the era of endoscopic ultrasound guided rendezvous

The rendezvous approach is a salvage technique after failure of endoscopic retrograde cholangiography (ERC). In certain circumstances, percutaneous-endoscopic rendezvous (PE-RV) is preferred, and endoscopic ultrasound-guided rendezvous (EUS-RV) is difficult to perform. We aimed to evaluate PE-RV outcomes, describe the PE-RV techniques, and identify potential indications for PE-RV over EUS-RV.Retrospective analysis was conducted of a prospectively designed ERC database between January 2005 and December 2016 at a tertiary referral center including cases where PE-RV was used as a salvage procedure after ERC failure.During the study period, PE-RV was performed in 42 cases after failed therapeutic ERC; 15 had a surgically altered enteric anatomy. The technical success rate of PE-RV was 92.9% (39/42), with a therapeutic success rate of 88.1% (37/42). Potential indications for PE-RV over EUS-RV were identified in 23 cases, and either PE-RV or EUS-RV could have effectively been used in 19 cases. Endoscopic bile duct access was successfully achieved with PE-RV in 39 cases with accessible biliary orifice using one of PE-RV cannulation techniques (classic, n = 11; parallel, n = 19; and adjunctive maneuvers, n = 9).PE-RV uses a unique technology and has clinical indications that distinguish it from EUS-RV. Therefore, PE-RV can still be considered a useful salvage technique for the treatment of biliary obstruction after ERC failure.

Recent Advances in Endoscopy

In this narrative review, invited by the Editors of Gastroenterology, we summarize recent advances in the field of gastrointestinal endoscopy. We have chosen articles published primarily in the past 2-3 years. Although a thorough literature review was performed for each topic, the nature of the article is subjective and systematic and is based on the authors' experience and expertise regarding articles we believed were most likely to be of high clinical and scientific importance.